Tech Chat | How to test the RTK performance?

2023-05-30

When using RTK equipment for surveying, the most important performance of RTK should be its accuracy and re-initialization time. The former determines the work quality, while the latter determines work efficiency.

Our previous blog has introduced multiple sources of RTK errors, we can tell that the RTK performance is not the same in different countries and different working environments. If you want to know exactly how your RTK receiver performs, you can test it by yourself. In today's blog, we'll introduce a simple way to test RTK performance in two aspects - accuracy and re-initialization time.

Preparation:

GNSS receiver, here we will take Y1 as an example.
Field surveying software, in this blog we will use SingularPad.
PDA device.

Test Scene:

Here we will introduce several typical scenes, you can select several points in each scene. If you have enough time or want to test in more detail, you can also choose more test scenes.

Scene 1: Open sky
Scene 2: Under the tree
Scene 3: Near the building

Base Station Setup:

As introduced in previous blog, the shorter baseline between the higher accuracy and faster re-initialization time. In order to see the affect of the baseline distance, we need to set a long baseline and a short baseline to test separately.

Short baseline: 100m between base and rover.
Long baseline: 10km between base and rover.

Note: You can set different baseline distances according to your daily work scenarios.

Test Method:

Step 1: Get reference coordinates of each test point
Set the smooth GPS point as 5-10, the point coordinates of this long-time smooth RTK solution will be used as a reference.

Step 2: Record the re-initialization time and measure the point coordinates after each re-initialization.

At each point, invert the RTK receiver and wait for the fixed RTK solution to become single-point solution. Then put the receiver upright, record the time from single-point to the fixed solution of the receiver, and then measure the point.

Repeat this process at least 5 times for each point in different test scenes.

Step 3: Summarize test data.

RTK accuracy: Compare the point coordinates of each test point with its reference, the error should be the accuracy of the IMU function.

RTK re-initialization time: Calculate the average value of re-initialization time, you can get a typical value of your RTK device performance in different working environments.

Here is a simple example of the test results of Y1 GNSS receiver. As shown in the table below, with strong satellite tracking and anti-interference capability, different environments and baseline distances have little effect on the re-initialization performance of Y1. The average time is within 3 seconds.